Wells are generally drilled into the ground or ocean bed to recover natural deposits of oil and gas, as well as other desirable materials that are trapped in geological formations in the Earth's crust. Wells are typically drilled using a drill bit attached to the lower end of a “drill string.” Drilling fluid, or mud, is typically pumped down through the drill string to the drill bit. The drilling fluid lubricates and cools the bit, and may additionally carry drill cuttings from the borehole back to the surface.
In various oil and gas exploration operations, it may be beneficial to have information about the subsurface formations that are penetrated by a borehole. For example, certain formation evaluation schemes include measurement and analysis of the formation pressure and permeability. These measurements may be essential to predicting the production capacity and production lifetime of the subsurface formation. When performing such measurements, downhole tools having electric, mechanic, and/or hydraulic powered devices may be used. To energize downhole tools using hydraulic power, various systems may be used to pump fluid, such as hydraulic fluid. Such pump systems may be controlled to vary output pressures and/or flow rates to meet the needs of particular applications. Pressurized fluid may then be communicated to the hydraulic powered devices in a tool string. Further, in some implementations, pump systems may be used to draw and pump formation fluid from subsurface formations. The pumped formation fluid may consequently be communicated to fluid sensors and/or storages vessels provided in the tool string.
A downhole string (e.g., a drill string, coiled tubing string, slickline string, wireline string, etc.) may include multiple modules, such as multiple components, connected to each other such that the modules are in communication with each other. For example, the modules may be in fluid communication and/or in electrical communication. Thus, the modules may have hydraulic and electrical connections to enable communication therebetween. Accordingly, the downhole string (and components thereof) may be susceptible to contamination when making and breaking module connections to assemble and disassemble the downhole string, such as fluid contamination from the hydraulic connections into the electrical connections.